CVE-2026-55839CWE-79cross-site-scripting

CVE-2026-55839

High · published August 18, 2026

CVSS v3.1
8.7
EPSS
0%
Percentile
36.2
In the wild
Unconfirmed
What it is

Kestra is an open-source, event-driven orchestration platform. Prior to 1.3.24, Kestra's custom Markdown parser in ui/src/utils/markdown_plugins/link.ts allows a user with permission to create or update a Flow description to inject JavaScript event-handler attributes through the custom [[link]] syntax, causing stored cross-site scripting when another user opens the description or information panel in the Flow list. This issue is fixed in version 1.3.24.

The record
Technical detail
CVSS v3.1
8.7 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00430 · 36.2th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-08-18T20:17Z
References (4)
https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e · [email protected]https://github.com/kestra-io/kestra/pull/16835 · [email protected]https://github.com/kestra-io/kestra/releases/tag/v1.3.24 · [email protected]https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8 · [email protected]
EPSS history
Timeline
  • 18 AUG 15:27Z
    Kestra: Stored XSS via custom Markdown [[link]] attribute injection
    cvelistv5